This invention relates generally to a prosthetic total knee replacement system, and more specifically, to a modular tibial support peg for securing the tibial component of a prosthetic total knee replacement system to a tibia.
The hyaline articular cartilage of a natural knee joint may undergo degenerative changes due to various etiologies. When these degenerative changes are advanced, irreversible and unresponsive to non-operative management, it may ultimately become necessary to replace the natural knee joint with an artificial knee joint prosthetic system.
An artificial knee joint prosthetic system generally includes a femoral component, a tibial component and a patella component. The femoral component is secured to the surgically prepared distal femur and is used to simulate the articulating surface of the natural femur. Similarly, the tibial component is secured to the surgically prepared proximal tibia and is used to simulate the articulating surface of the natural tibia. The tibial component generally includes a tibial insert UHMWP liner, which articulates directly with the femoral component, and a metal backed portion which may include pegs and a tibial stem. This metal backed portion is used to provide secure support to the UHMWP liner as well as provide optimum fixation of the tibial component to the tibia. Finally, the patella component articulates with the patello-femoral groove of the femoral component.
There are several mechanisms which may be used for securing the tibial component to the tibia. Generally, a tubular cavity is formed in the proximal tibia which is used to receive the tibial stem of the metal backed portion of the tibial component. In addition, bone screws may be used which insert through counterbores in the metal backed portion and may extend to the corresponding tibial cortical surfaces. Integral flat or fluted modular solid pegs may also be used to enhance the fixation of the tibial component to the surgically prepared proximal tibia.